Ground rod bond



Sept. 16, 1952 m s 2,611,001

GROUND ROD BOND Filed Sept. 14, 1950 INVENTOR FPZWE/P/CA 6. @9501;

ATTO EY "Patented Sept. 16, 1952 GROUND ROD BOND Frederick G. Ridgers Hamilton; Ontario, Canada,

assignor to N. Slater Company Limited, Hamil ton, Ontario, Canada I Application September 14, 1950, Serial No.1841773 This invention relates to electrical grounding devices and has special reference to the devices known as ground rods.

Such devices take the general form of long rods driven into the ground usually at a point some distance from the structure or element which it is desired to maintain in grounded con dition, a Wire leading from such structure or element and having its lower end connected to the upper end of the rod. Obviously such a rod should be of electrically conductive material but of an economical character.

The connection of the grounding wire to such rods is a field operation and one general manner of making such connection is to place a clamp around the rod which acts either to grip the wire against the rod or to have the wire attached or connected to the clamp. Since it is sometimes the practice to drive the rod to such depth that its upper end is about six inches below the surface any such clamping device and the upper part of the rod are exposed to corrosion and while the rod may have its upper part galvanized yet the zinc itself is subject to oxidation. The conductive connection between the wire and the rod is thus apt to become imperfect.

It is the principal object of the present invention to provide a connection between the ground rod and the grounding wire which will be highly conductive and not subject to such corrosion or oxidation as exists in the present known connections.

Another important object of the present inventlon is to provide a novel construction of ground rod having highly conductive non-corrosive parts welded thereto for engagement by the grounding wire.

A further object of this invention is to provide a novel form of connection for the grounding wire in which a track or fish plate bolt and a nut are used to hold the parts together.

Still another object is to provide simple means for removing the ground wire while testing the ground rod.

With the above and other objects in View, as will be presently apparent, the invention consists of certain novel arrangements of details and combinations of parts hereinafter fully described, illustrated in the accompanying drawings and particularly claimed.

In the drawings like characters of reference indicate like parts in the several views, and:

Figure 1 is a side elevation of a ground rod constructed in accordance with this invention 1 Claim. (Cl. 174-7) 2 showing one species of ring used herein in position on the rod. I

Figure 2 is a section on the line 2--2 of Fi urel.

Figure 3 is a side elevation of the upper end of the rod showing a second ring which may be used herein.

Figure 4 is a section on the line 4- of Figure 3.

Figure 5 is an enlarged fragmentary section of a form of contact ring adapted to be used in this invention.

As shown in the drawings, the present embodiment consists of a rod having a length of several feet and a diameter, say from three-eighths of an inch to one inch. The body 10 of this rod terminates downwardly in a long sharp point i l The upper end of the rod is forged, as by upsetting, to produce a bulged portion 12 just below the end face of the rod. This portion l2 has a pair of parallel side faces 53 and a bolt hole it extends between the faces E3. The faces l3 are preferably spaced a distance equal to the diameter of the rod.

On one or both of the faces i3 is mounted a ring [5 of highly conductive metal of corrosion and and oxidizing inhibiting material. Each ring I5 is welded as at 16 to the rod metal. The rings l5 may be of solid copper, but stainless steel is found, for the purpose of this invention, to be of sufliciently high electrical conductivity and may be readily welded to the rod. A form of ring is shown in Figure 5 which is stamped from sheet steel l8 whereon a copper face I9 has been rolled during the production of the sheet. While the foregoing materials provide excellent rings for this purpose other materials may be used, the essential features being that the material shall be firmly welded to the rod and that the material shall inhibit corrosion and oxidation tending to injure the welded contact with the rod.

In order to secure the wire to a rod constructed as above described a track or fish plate bolt 20 is inserted through the conforming hole l4, here shown as oval, with its head 2! bearing on one ring I5 or, when only one ring is used, on the flat side I3 of the rod itself. The head 2| is preferably a snap or round head. The bolt has a washer 23, preferably of copper, mounted thereon to be urged toward the rod ID by a nut 24, and the washer is preferably formed to curl about the rod in an embrace above and below the bulge [2 to keep from turning with the nut as the latter is tightened, and further forms a guard and guide for the ground wire. These inturned portions are indicated by 2311. In attaching the wire 25 it is looped and the loop is placed between the washer 23 and the adjacent ring I5. The nut 24 is then tightened up and the Wire 25 tightly clamped between the Washer 23 and the adjacent ring I5. There is thus provided a permanent but separable connection between the wire 25 and rod It and one in which there can be no break in the current conducting path.

Further, it will-The observed that the structure herein vfacilitates detachment of the ground wire from the ground rod for the purpose of running the conventional periodic ground rod resistance tests and again making the connection withathe maximum of effective current contact capacity.

In assembling the rod andring; :i't is Well to first. weld the ring to the uncoated rod, then galvanize the assembled rod and ring, and finally remove the zinc from the face of thearinghygrindingeor.

otherwise. 7

What is claimed is: In combination, a ground rod having a bulged portion: adjacent its "upper extremity, said bulged portion having a pair of fiat parallel :sides'and having an oval shaped bolt receivingppening extending between said sides, a ring of material,

'BIEEERENCES CITED iheioliowing references are of recordrin the file of this patent:

UNITED STATES PATENTS Number Name Date-- 2,004,999 McIlvane r June 18, 1935 2,354,081 Weder July 18, 1944 2,537,463 Hocher,. Jan. .9, 1951 

